October 2019

ASCRS NEWS

JCRSJournal of Cataract & Refractive SurgeryIn the journal: October 2019

Phakic intraocular lens for the correction of hyperopia: a review

Abdulaziz Alshamrani, MD, Saad Alharbi, MD
A literature review pulled together safety and efficacy data for phakic intraocular lens (pIOL) correction of hyperopia and hyperopic astigmatism, finding that current options on the market are both safe and effective. Anterior chamber iris-fixated pIOLs and posterior chamber implantable collamer lenses (ICL) are the current options for hyperopia and hyperopic astigmatism correction. In the literature review, the authors noted no serious complications and wrote that pIOLs “may be the optimal refractive surgery for the correction of high hyperopia.

The accuracy of thick-lens intraocular lens power calculation based on cutting-card or calculated data for lens architecture

Kristian Næser, MD, Giacomo Savini, MD
As the authors of this retrospective case series put it, “most intraocular lens (IOL) power formulas employ a thin-lens approach” to calculate effective lens position. This, they continued, assumes that the total IOL power is “located in the ELP rather than … distributed on the anterior and posterior lens surfaces.” The authors compared the accuracy of the Barrett Universal II, Haigis, Hoffer Q, Holladay 1, and SRK/T formulas and thick-lens formulas (Næser 1, which uses manufacturers’ data, and Næser 2, which uses calculated data), the latter of which, “[relies] on anatomically and optically correct eye models.” Prediction error in refraction was retrospectively calculated in 141 eyes that received an Alcon SN60WF IOL and “predictions made using the different formulas were optimized in retrospect by adjusting the respective constants.” Both Næser thick-lens formulas were similar in accuracy and performance when compared to the thin-lens formulas.

Laser-assisted in situ keratomileusis flap lift for refractive enhancements after five and ten years: safety and efficacy

Jorge Alió del Barrio, MD, Rana Hanna, MD, Mario Canto-Cerdan, OD, Alfredo Vega-
Estrada, MD, Jorge Alió, MD
Is lifting a LASIK flap for refractive enhancement safe after 5 years? Is it safe after 10 years? That’s what Alió del Barrio et al. sought to evaluate in a retrospective case series study. The study included 70 eyes that had myopic (n=45), hyperopic (n=22), and presbyopic LASIK (n=3) with 12.3±3.45 years elapsing from the original LASIK procedure to the flap lift for enhancement. Flap lift was 10 years or more in 57 eyes. Mean spherical equivalent before the refractive enhancement was –1.29±1.23 in the myopic group and +0.65±1.72 D in the hyperopic group. After the flap lift and enhancement, 88% of myopic eyes and 74% of hyperopic eyes were 20/20 or better UCVA; 100% were at least 20/25. There was mild epithelial ingrowth in 31.43% of cases and clinically significant epithelial ingrowth in 11.42% of cases. About 4% required another flap lift due to severe epithelial ingrowth. With these findings, Alió del Barrio et al. concluded that “late flap lift for refractive enhancement 10 years or more after LASIK is a feasible alternative with good levels of efficacy and safety together with a fast visual recovery.”

In the journal: October 2019 In the journal: October 2019 Ophthalmology News - EyeWorld MagazineOphthalmology News - EyeWorld Magazine